The Best Book Reviews Money Can Buy

Reviews by ordinary people have become an essential mechanism for selling almost anything online; they are used for resorts, dermatologists, neighborhood restaurants, high-fashion boutiques, churches, parks, astrologers and healers — not to mention products like garbage pails, tweezers, spa slippers and cases for tablet computers. In many situations, these reviews are supplanting the marketing department, the press agent, advertisements, word of mouth and the professional critique. But not just any kind of review will do. They have to be somewhere between enthusiastic and ecstatic. “The wheels of online commerce run on positive reviews,” said Bing Liu, a data-mining expert at the University of Illinois, Chicago, whose 2008 research showed that 60 percent of the millions of product reviews on Amazon are five stars and an additional 20 percent are four stars. “But almost no one wants to write five-star reviews, so many of them have to be created.” Liu estimates that about one-third of all consumer reviews on the Internet are fake. Yet it is all but impossible to tell when reviews were written by the marketers or retailers (or by the authors themselves under pseudonyms), by customers (who might get a deal from a merchant for giving a good score) or by a hired third-party service.